OliSERVATIOXS ON TllK liKSSlAN I'LV. iU'} 



not know what it is which has caused their crops to present such 

 weakness. It is of no use relying upon the farmers to notice 

 these crop pests, for not one out of fifty knows the appearance of 

 the Plessian Fly; and we must not imagine it to be exterminated 

 simply because the farmers have not reported it. So far from 

 being exterminated, this special pest has been having a fine time 

 of it during 1893 in South Devon, where, during a fortnight's 

 holiday in August and September, I found it in the greatest pro- 

 fusion, principally in the puparium state, though many larvae were 

 also found, and since covering in the infested stubble collected, 

 many of the flies have emerged, besides a few parasites. 



The immunity from all interference which the Hessian Fly 

 and other crop pests enjoy in " our right little, tight little island," 

 does not tend to decrease their number, so that we must not be 

 surprised to find many wheat and barley fields held in possession 

 by this most persevering enemy. Many of the fields examined in 

 South Devon were " eaten up with maggots," the typical bent 

 straws indicating the presence of the pest were to be seen on 

 every side in wheat and barley fields alike. Their backward 

 state in May and June rendered the plants particularly favourable 

 for the reception of eggs from the main brood, no doubt every 

 female doing her best to be fruitful and multiply by laying the 

 full complement of some one hundred and fifty eggs, distributing 

 them over some dozen or twenty plants, in many cases at both 

 first and second joints of one stem. Only to-day (Sept. 3ist) on 

 one, but two inches long, I found eight at the first knot and four 

 at one above. I paid my last visit to a wheat field, Sept. 4th, 

 when I found the crop cut, so was enabled the better to examine 

 the stubble ; on pulling up a number of plants, I found puparia 

 on every one, without exception. Six of them yielded sixty-three, 

 while from one alone I took no less than twenty-seven, most 

 of which were close down at the base of the stems, below the 

 ground-line. Tlie owner told me he did not reckon he should get 

 more than three bushels per acre, while others " were not worth 

 cutting." By far the greater nuuiber of these " flax-seeds " are 

 left in the stubble, protected from all harm and chance of being 

 destroyed, the clover or grass, with which most of the fields are 

 laid, forming an additional protection later on, so that a vast 

 number of flies will emerge next year, ready to spread through 

 neighbouring fields. The only remedy which can be applied is 

 to plough the field, run the scuffler through, collect the stubble 

 into heaps and burn them. 



There is an old saying about " a little learning being a 

 dangerous thing," but I do not think it would be in the case of 

 the Hessian Fly, as it might prevent the farmers from ignorantly 

 putting in a crop of puparia each year, by spreading the screenings 

 from the threshing machine with the rough manure. This I 

 found to be the habit of every farmer to whom I spoke. Nothing 



